serial communication between ATmega128 and Spartan 3E

[arash rezaee]

Hi every one.

I want to send 5 digit number from Atmega128 to FPGA(Spartan 3E). Let say for example I want to send 19999 into FPGA and then use it for my project. What is the best way for this communication?

Regards
Arash

 

[barry]

How far apart are the devices? What speed do you need? Personally, I would use a simple serial link. If you've got a lot of extra pins, you could do it parallel.

 

[arash rezaee]

Hi again.

Well I decided to use SPI between Atmega and Spartan. But I have little problem. I have a number like 19999 and I want to convert it to hex and then send it via SPI. How can I convert it?

Regards
Arash

 

[broodell]

You don't have to convert it before transmitting. The following will all store the same value in i ("0x" denotes hex, "0b" denotes binary):

int i;
i = 16;
i = 0x10;
i = 0b10000;

 

[barry]

Why do you need to convert to hex? You can convert each character to ASCII if you want, but that will require more bytes. If you know your maximum number size (for example 19999) you can just send it as a 4-byte message-you don't have to convert.

 

[alexxx]

Why do you need to convert to hex? You can convert each character to ASCII if you want, but that will require more bytes. If you know your maximum number size (for example 19999) you can just send it as a 4-byte message-you don't have to convert.

+1.

Or if you know for example that the number is always smaller than 65535 (0xFFFF), then you could split it in two bytes and send each byte in separate.